Connecticut’s two casinos have settled into a firm pattern of year-over-year declines in revenue now that Massachusetts’ first casino in Springfield has established itself.

MGM Springfield counted revenues of $21.82 million in April, a 15 percent decline from the roughly eight-month-old casino’s best revenue month in March, according to numbers released by the state Gaming Commission. Players wagered $174.95 million on the slot machines at MGM last month, and while 91.16 percent of it was returned to players as winnings, MGM Springfield reported $15.47 million in gross slot revenue in April. The casino collected another $6.35 million in revenue from its table games.

In Connecticut, where the Department of Consumer Protection only releases statistics about the slot machines at the Foxwoods and Mohegan Sun casinos, the latter saw its revenues drop 11.9 percent on a year-over-year basis, while the former saw its revenues drop by 12.1 percent.

MGM Springfield this summer “will reaffirm our commitment to the community and commonwealth through a robust calendar of events, exciting outdoor MGM LIVE concerts, sensational shows at Symphony Hall, eclectic food and beverage options in our bars and restaurants, and a dynamic series of winning casino promotions,” MGM Springfield President Michael Mathis said in a statement, adding that the casino was pleased with its performance.